sudo: false
dist: trusty

language: node_js

node_js:
  - "9"

os:
  - linux
  - macosx
  - windows

matrix:
  include:
  - node_js: 9
    os: linux
    env: USE_NPM=true
  - node_js: 8
    os: linux
  - node_js: 6
    os: linux

cache:
  yarn: true

before_install:
  - if [ "$USE_NPM" == "true" ]; then rm yarn.lock; fi

before_script:
  - if git status | grep -q "modified.   \.travis\.yml"; then echo "Dirty yarn.lock"; exit 1; fi

script:
  - gulp